Photobombing is an art, the art of being at the right place at the wrong time. It also requires a huge amount of skill and courage.
At certain times, people are so careless that the situation they land up in unknowingly becomes hilarious without their efforts. At other times, people deliberately cause situations which make these photobombing fun.
If photobombing is practised on you, it is evil but if you are the one doing it, it's ludicrous. here are a set of hilarious photobombs ever.